Archive for December, 2011

A very good morning guys. I couldn’t sleep tonight just because of ongoing India-Australia Test Match at Melbourne and while it’s more than half an hour before the play begins let’s have some talk over network tools in Linux.

There are some common tools like ping traceroute and netstat which provides valuable information about our network connection and traffic. So here we’ll get all these tools at one place so that we can use them easily. So first of all issue this command on your RHEL machine-

yum install gnome-nettool

And that’s all you need to do. Now go to your Terminal and issue gnome-nettool command and you’ll see the following screen

This includes Ping Netstat Traceroute Portscan Lookup Finger and Whois which you can use from an easy to use graphical interface. So get set and go.

This is the topic I was trying to do for many days but it was not working. Finally I have done it and it’s time to share it with you guys. So following are the steps to do this task-

Open /etc/pam.d/system-auth file.

Now write these lines just above the line stating auth sufficient pam_unix.so:

auth required pam_tally2.so onerr=fail deny=3

account required pam_tally2.so reset

Now the account will be locked after three failed login attempts. There are various other options you can use like-

unlock_time=100 will unlock the account after 100 seconds. You can use any value for unlock_time field. If you don’t use this parameter then you’ll have to manually unlock a locked account using pam_tally2 -r -u username command.

lock_time=100 will lock the account for 100 seconds after failed attempts to login.

no_magic_root will avoid locking root account.

This is more than enough guys but for any additional help you can see the respective man pages.